Abstract
Saudi Arabia has been in rapid economic growth in recent years resulting in an increase in electricity consumption. Air-conditioners (A/Cs) are responsible for 50% of the electricity consumption due to hot weather conditions as well as the delay in implementing A/Cs performance standards. One challenge is that most A/Cs in existing buildings are old and have been installed before standards on A/Cs were enforced in 2013. Renewing old A/ Cs with new and efficient ones would reduce electricity consumption, benefiting building owners as well as utility companies. Furthermore, new A/ Cs units are equipped with more environmentally friendly refrigerant, R410A, than old A/ Cs which use R22, a phased out refrigerant. In this research, six used split-type units that have ages from 3 to 32 year's were tested in Saudi Standard, Metrology and Quality Organization (SASO) A/C testing lab and their performances were compared to new units. All tested units have a rated cooling capacity of 18,000 BTU/hr. Tests were performed according to ASHRAE as well as SASO cooling test conditions. Test results show that EER and cooling capacity of the used split-type units compared to the new one are 68% and 93%, respectively. Such performance degradation would be more profound if the new unit uses R22 instead of R410A. Payback periods were investigated for different annual operation hours and different electricity rates, representing different sectors in Saudi Arabia. A map was developed showing economically feasible A/Cs replacement regions for different desired payback periods at different operation hours and electricity rates. The developed map can help the government or building owners on deciding when to renew existing split-type A/Cs. The results show that if the government replaces 2 million used split-type units, 4.17 million tons of C[O.sub.2] per year will be saved and the peak load on the utility will be reduced by 1.48 GW. Last, the effect of replacing the used unit compressor-, which is the heart of the A/ Cs, with a new compressor was investigated.